With rapid development of network engineering nowadays, a keyboard-video-mouse (KVM) switch interconnecting between a console and a plurality of computers is widely utilized to transmit KVM signals therebetween for remotely controlling the plurality of computers from the console. An on-screen display (OSD) menu interface concept is raised for convenience of operation on controlling the plurality of remote computers. The user can directly select any one of the plurality of computers from the OSD menu graphically presented on a displayer coupled to the console. Originally, it is designed only for connecting to fewer computers due to a restricted remote control ability of the KVM switch. However, the design of the KVM switch has greatly been improved on aspects of functions. Especially, the number of computers joined to the network can be greatly increased for complying with explosive growth of various network neighborhoods. Even multiple KVM switches can be constituted in daisy chain or cascade with each other. Sometime, the number of computers joined to the multiple KVM switches in daisy chain and cascade can reach up thousands. Obviously, as shown in FIG. 2, a traditional OSD menu is entirely composed of pure texts. It will be laboriously for any user to seek one by one and then access each desired computer coupled to the KVM switch. For example, by multiple-level cascades, e.g. five levels, or even eight levels, the user has to sequentially access these levels to find out the desired computer. Without a prepared detail list relative to all the computers, it will be hardly found out the desired computer because the OSD menu composed of pure text reveals little information related to the desired computer. Furthermore, the user has to waste lots of time to manipulate such an un-humanized interface to get better skill in operation.
Several prior arts adoptive of said traditional OSD menu technology have been disclosed in U.S. Pat. Nos. 5,721,842, 5,884,096, 5,937,176, 6,112,264, 6,345,323, and U.S. Patent Application Publication No. 20020087753. Further referring to FIG. 1, an exemplar showed that an on-screen display (OSD) menu was constructed by video signals generated from an on-screen display (OSD) circuit 14, e.g. an OSD Chip. Then the video signals of the on-screen display (OSD) menu are transmitted to an overlay circuit 12. The overlay circuit 12 is able to simultaneously receive and combine the real-time video signals from a remote computer and the video signals of the OSD menu. While the user wakes the OSD menu up to select one of the computers from a monitor of the console device, an overlay signal generated by combining the real-time video signals from the selected computer with the video signals related to the OSD menu is outputted to the monitor. As a result shown in FIG. 2, a traditional OSD menu image graphed over a managing image from the selected computer is displayed on the central position of the monitor 212. The OSD circuit 12 is used for generating the video signal of the OSD menu. An overlay circuit 14 is used to combine the real-time video signal from the computer and the video signal of the OSD menu. Nevertheless, the signal processes for both the OSD circuit 14 and overlay circuit 12 are greatly complicated. That is because that the overlay circuit 12 according to a keyboard/mouse signal (OSD menu enable signal) through the KVM switch 18 to determine whether the video signal of the OSD menu or the video signal from the computer is outputted for every single pixel on the monitor.
Consequentially, there's a need to set forth a system and method for controlling remote computers having greater convenient operation and better-humanized interface.